nsIScriptError

Implemented by: @mozilla.org/scripterror;1. To create an instance, use:

var scriptError = Components.classes["@mozilla.org/scripterror;1"]
                  .createInstance(Components.interfaces.nsIScriptError);

Method overview

Attributes

Flag constants

Methods

init()

Initializes the object with information describing the error which occurred.

void init(
  in wstring message,
  in wstring sourceName,
  in wstring sourceLine,
  in PRUint32 lineNumber,
  in PRUint32 columnNumber,
  in PRUint32 flags,
  in string category
);

Parameters

message

The text of the message to add to the log.

sourceName

The URL of the file in which the error occurred. This will be a hyperlink in the JavaScript Console, so you should use a real URL. You may pass null if it's not applicable.

sourceLine

The line number in the source file on which the error occurred. You are responsible for providing that line. You may pass null if you are lazy; that will prevent showing the source line in JavaScript Console.

lineNumber

The number of the line where the error occurred.

columnNumber

The column number where the error occurred. This is used to draw an arrow pointing to the problem character.

flags

One of flags listed in Flag constants.

category

A string indicating what kind of code caused the message. There are quite a few category strings and they don't seem to be listed in a single place. See Categories for a partial list.

initWithWindowID()

Initializes the nsIScriptError object with the given inner window's ID.

void initWithWindowID(
  in wstring message,
  in wstring sourceName,
  in wstring sourceLine,
  in PRUint32 lineNumber,
  in PRUint32 columnNumber,
  in PRUint32 flags,
  in string category,
  in unsigned long long innerWindowID
);

Parameters

message

The text of the message to add to the log.

sourceName

The URL of the file in which the error occurred. This will be a hyperlink in the JavaScript Console, so you should use a real URL. You may pass null if it's not applicable.

sourceLine

The line number in the source file on which the error occurred. You are responsible for providing that line. You may pass null if you are lazy; that will prevent showing the source line in JavaScript Console.

lineNumber

The number of the line where the error occurred.

columnNumber

The column number where the error occurred. This is used to draw an arrow pointing to the problem character.

flags

One of the script error Flag constants

category

A string indicating what kind of code caused the message. There are quite a few category strings and they aren't listed in a single place, so you may need to search the Firefox code to find the one you want. See Categories for a partial list.

innerWindowID

The ID of the inner window associated with the error.

toString()

Outputs a string representing the error message described by the object.

AUTF8String toString();

Parameters

None.

Return value

A string representing the error message described by the nsIScriptError object.

Examples

Logging a message with additional information

In this example nsIScriptError, which implements nsIConsoleMessage, is used to log information to the console including information about the source file and line number of the error.

function myLogToConsole(aMessage, aSourceName, aSourceLine, aLineNumber, 
                        aColumnNumber, aFlags, aCategory)
{
  var consoleService = Components.classes["@mozilla.org/consoleservice;1"]
                                 .getService(Components.interfaces.nsIConsoleService);
  var scriptError = Components.classes["@mozilla.org/scripterror;1"]
                              .createInstance(Components.interfaces.nsIScriptError);
  scriptError.init(aMessage, aSourceName, aSourceLine, aLineNumber, 
                   aColumnNumber, aFlags, aCategory);
  consoleService.logMessage(scriptError);
}

Categories

There are a lot of categories, and they're not all maintained in a single list anywhere in the code. This is an attempt to group them together for reference. Note that these are strings. If you want to log an error at chrome level you should set a Category from the first section (leaving it empty might log it as content error). As Addon author I would recommend using "chrome javascript" for logging exceptions caused by addon code.

Categories the Web Console does not display

• "XPConnect JavaScript"
• "component javascript"
• "chrome javascript"
• "chrome registration"
• "XBL"
• "XBL Prototype Handler"
• "XBL Content Sink"
• "xbl javascript"
• "FrameConstructor"

Categories the Web Console displays

• "HUDConsole"
• "CSS Parser"
• "CSS Loader"
• "content javascript"
• "DOM Events"
• "DOM:HTML"
• "DOM Window"
• "SVG"
• "ImageMap"
• "HTML"
• "Canvas"
• "DOM3 Load"
• "DOM"
• "malformed-xml"
• "DOM Worker javascript"
• "Mixed Content Blocker"
• "CSP"
• "Invalid HSTS Headers"
• "Insecure Password Field"

See also

• Using the Web Console
• Error Console
• nsIConsoleMessage
• nsIScriptError2